The optimal conditions for storage of many fruits and vegetables are difficult to create in a standard household refrigerator. The ideal temperature for the storage of moderate temperature fruits and vegetables is generally between forty (40) and sixty-five (65) degrees Fahrenheit (approximately 4-18 degrees Celsius). The fresh food compartment of most household refrigerators is kept at a temperature below what is ideal for storage of these fruits and vegetables, in order to provide appropriate conditions for storing other fresh foods such as milk, eggs, meat, and beverages.
Additionally, the humidity level in the fresh food compartment may be too low as a result of the moisture that is naturally removed from the chilled air that cools the fresh food compartment. The difficulties of low humidity may be compounded by any blowing or other movement of air in the fresh food compartment that may accelerate the evaporation process. As a result, if the humidity level of the fresh food compartment is too low, it will cause excessive desiccation of the fruits or vegetables, which is not desirable. On the other hand, if the humidity level is too high, that results in excessive condensation of water, which creates its own problems. Ideally the humidity level will be approximately ninety percent (90%) relative humidity.
As produce ripens, it produces ethylene gas. Ethylene gas acts as a catalyst to stimulate additional ripening and eventually senescence. Typically storage times for fruits and vegetables can be enhanced by eliminating excess ethylene from the air. On occasion, it is desired to ripen produce more rapidly. On these occasions it is desirable to retain the ethylene gas in close proximity to the fruit in order to accelerate the natural ripening process. Apples and tomatoes produce relatively high levels of ethylene gas.
Different fruits and vegetables may benefit from different storage conditions. As a result, it is beneficial to have separate compartments in order to permit different storage conditions for various fruits and vegetables at the same time.
While it is known in the art to provide separate compartments within household refrigerators for storage of fruits and vegetables, these compartments commonly lack some or all of the features necessary for optimal storage of moderate temperature fruits and vegetables.
What is needed in the art is a household refrigeration unit that is dedicated to the storage of moderate temperature fruits and vegetables. Preferably the unit will allow control of temperature in a range of 40-65 degrees Fahrenheit (4-18 degrees Celsius), control of humidity levels to prevent excessive drying of the fruits and vegetables and to prevent excessive condensation, and control of ethylene gas levels to accelerate or retard ripening.